problem with variants display on product page

-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.5
-- PHP version -- : 7

I'm having a problem displaying the variants' images.

When I change the color from grey to red for example, the image updates. but when I want to come back to the previous color, then the image does not update. I have then to change the size in order to see the image change.

other problem is that the lightbox works on the thumbnails, but only before I change the color. the lightbox will not work once I have changed the color of the variant (and thus changed the displayed thumbnails.

Is that a known bug or am I doing something wrong ?

Many Thanks
Raphael

Hi Philip,

Sorry, I was pretty sure to have added the url but I obviously didn't.
Here is an example:
capsulz.ru/index.php/woman/product/5037-...башка-платье{-langck }

Many thanks for your help
Raphael